Robert Louis Stevenson (1850-1894) married Frances "Fanny" Van de Grift Osbourne (1840-1914) in May 1880. They could not afford the $10 a week to stay at a hotel, so they spent their honeymoon with her son, Samuel Lloyd Osbourne (1868-1947), in an abandoned three-story bunkhouse at a derelict mining camp called "Silverado." They squatted for two months, and he later wrote about it in "The Silverado Squatters." Many of his notes on the scenery later provided much of the descriptive detail for "Treasure Island."
Treasure Island was originally serialized in the children's magazine "Young Folks" from 1881 through 1882 under the title "Treasure Island or the mutiny of the Hispaniola." It was later published in Nov 1883.